Forty-five previously untreated patients with primary carcinoma of the vagina were treated with curative radiotherapy from 1965 through 1985. All patients were staged according to the FIGO system. One patient was classified as Stage 0, 15 as Stage I, 22 as Stage II, 6 as Stage III, and 1 as Stage IV. Treatment consisted of intracavitary irradiation alone in Stage 0 patients. Stage I patients received intracavitary/interstitial irradiation alone or in combination with external irradiation and an implant when feasible. When treated with an implant only, the total tumor dose delivered was between 65-70 Gy. External irradiation consisted of delivering a dose of 45-50 Gy over a period of 4 1/2-5 weeks to the whole pelvis to treat the regional lymph nodes. An additional dose of 20-25 Gy was delivered to the site of original involvement using an implant when feasible. If not technically feasible, as in advanced stages, the patient was treated with additional external irradiation to a total dose of 65-70 Gy by a shrinking field technique. All patients except one were followed either until death or for a minimum of 2 years. The actuarial 5-year survival rates were 100% for Stage 0, 78% for Stage I, and 71% for Stage II patients. None of the patients with Stage III or IV disease survived. Of the patients who recurred, all but two did so within 16 months after diagnosis. Pelvic recurrence as the first site of recurrence occurred in 86% of the patients who recurred. Distant recurrence as a component occurred in 20% of all failures. Complications as a consequence of therapy occurred in 18% of the patients. Vaginal necrosis that healed with conservative treatment was seen in four patients and the other four patients had rectal complications of varying severity. Thus, curative radiotherapy is an effective method of treatment, with acceptable morbidity, in patients with early stage primary carcinoma of the vagina.